Lifting jack



Dec. 13, 1927.

1,652,821 A. B. FEE HERN ET AL LIFTING JACK Filed June 15. 1927 f I'NVENTOR$=' fill.

Patented Dec. 13, 1927.

UNITED. STATES PATENT OFFICE.

AUNCEL BRIAN FEE HERN AND ALBERT HENRY FEE KERN, 0]! LONDON, ENGLAND.

LIF'IING JACK.

. Application filed June 13, 1927, Serial No 198,658, and in Great Britain December 2, 1985- This invention relates to lifting devices or jacks of the type comprising a plurality of toggles adapted to be'operated by nut and screw mechanism and the object of the in vent-ion is to provide an improved jack of this class which is of simplified construction and capable of relatively considerable expansion or contraction.

The lifting device or jack according to the invention comprises a base portion and a crutch portion connected to each other at each side by pairs of toggles the upper and lower ends of which are crossed and pivotally connected to said portions at spaced points, the centre pivots of the toggles being connected by nut and screw mechanism, means being provided to cause the crutch and base to move towards or away from each other in, the vertical axis of the device dur-' ing expanding or contracting movements. The said means may comprise pairs of drifting links connected to said centre pivots and associated with the base and crutch, and the appropriate ends of the drifting links may 4 be connected to pins engaging slots in the base and crutch portions.

The connecting points on the crutch and base may be equally spaced on opposite sides of the vertical axis.

.The nut and screw mechanism may comprise a block rotationally connected to one end of the screw, and a nut element, the

lock and nut being provided with trunnions by which they are pivoted to the toggles and drifting links.

In the accompanying drawings illustrating a jacking device according to the invention, Figure 1 is an elevation of the jack partly extended whileFigure 2 is an end elevation corresponding ther 'to.

In carrying the invention into effect ac cording to one convenient mode, a. base 3 is provided having a shoe 4. The base member is connected by pairs of toggles to a crutch 5.

The toggles are duplicated on either side of the jack as will be seen from Fig. 2 and for convenienceof description only those on one side will be referred to.

The toggle comprising the links 6 and 7 are pivotally connected at their outer ends to the crutch and base by pins8 and 9 respectively while a second pair of links 6 and 7* are pivotally connected by the pins 8 and 9. The apart and the 6 and 6" cross one another. Similarly the pins 9 and 9 are ins 8 and 8 are spaced spaced apart an equal amount and the links The opposite end of the operating screw 14. is provided with a reduced lain part engaging an aperture in the bloc 12, a thrust ballbearing enclosed by the collar 17 being provided.

In order to steady the device and prevent tilting out of the vertical when in use, pairs of drifting links are provided. Thus one pair 18, 18 is pivotally connected to the trunnion 11 while a second pair 19, 19is pivotally connected tothe trunnion 13.

The free ends of these drifting links are connected together by the pins 20, 21 associated respectively with the crutch 5 and base 3. The pins 20, 21 pass through slots 22, 23, and are connected to the corresponding links on the other side of the jack. The slots are arranged in the vertical axis of the device and are slightly larger than the di-' ameter of the pins.

In assembling the various links on each side of the jack the may be mounted in such order as to lie in p anes adapted to facilitate the collapsing of the jack, and distance pieces or washers may be inserted where necessary.

The base 3 may be rovided with a recess 24 to accommodate t e screw 14 when thejack is collapsed and the shoe 4 may be curved at the endsas at 25 to facilitate its insertion under a vehicle.

The crutch 5 may be provided. with grooves 26 to accomodate the curved part of an axle or casing of a vehicle.

The crutch may be cast or formed of aluminum or other light material and having slotted steel plates 27 inserted in saw-cuts or grooves therein and riveted thereto for strengthening purposes, such plates extending downwardly a suitable distance according to the size of the slots 22.

Instead of fastening the plates by inserting them in theagrooves and rivetin they may be position in the casting m'oifid and the aluminum or the like cast around them, so as securely to hold them in position, the plates, if necessary, being suitably shaped to form a good joint Alternatively, the whole of the crutch part may be formed in one-casting of any suitable material. n

1 According to another modification, the crutch and if desired the base may be formed of stamped sheet metal, suitably bent into channel form.

We claim 1; A liftin jack comprising a base, a top,

nut having 'a pair of laterally extending trunnions, pairs of crossed lifting bars ivoted on said trunnions and extending to the top and base to which they are pivotally connectedat pairs of spaced points, vertically extending guiding slots on the top and base, guide pins disposed in said slots and pairs of guide links pivotally mounted at one end on said pins and at the other end on said trunnions.

2. A lifting jack as claimed in claim 1 wherein the lifting and guide bars extending respectively above and below the operating screw are symmetrically arranged.

'AUNCEL BRIAN FEE HERN. ALBERT HENRY FEE HERN. 

